The Chest Register
When the vowel a, as in man, was sung, I could, after long-continued practice, plainly see how the arytenoid cartilages quickly rose with their summits in their mucous membranous case and approached to mutual contact. In like manner, the chordæ vocales, or inferior vocal chords, approached each other so closely that scarcely any space between them was observable. The superior or false vocal ligaments formed the ellipse described by Garcia in the upper part of the glottis.
When, in using the laryngoscope upon myself, I slowly sang the ascending scale, this movement of the vocal chords and arytenoid cartilages was repeated at every tone. They separated and appeared to retreat, in order to close again anew, and to rise somewhat more than before. This movement of the arytenoid cartilages may best be compared to that of a pair of scissors. With every higher tone the vocal ligaments seemed more stretched and the glottis somewhat shorter.—[The glottis is a term applied to the space occupied by the vocal chords (the lips of the glottis): when separated, we say the glottis is open, when they touch, that it is closed.]—At the same time, when I sang the scale upward, beginning with the lowest tones, the vocal ligaments seemed to be moved in their whole length and breadth by large, loose vibrations, which extended even to all the rest of the interior of the larynx.
The place at which the arytenoid cartilages, almost closed together, cease their action and leave the formation of the sound to the vocal ligaments alone, I found in the entire vibration of the glottis, or in the chest register of the female voice, at do do♯ (c¹ c♯¹), more rarely at si (b). In the chest register of the male voice this change occurs at la si♭ (a b♭). With some effort the above-mentioned action of the arytenoid cartilages may be continued several tones higher. But such tones, especially in the female voice, have that rough and common timbre which we are too often compelled to hear in our female singers. The glottis also, in this case, as well as the parts of the larynx near the glottis, betrays the effort very plainly; as the tones ascend, they grow more and more red. Thus, as at this place in the chest register there occurs a visible and sensible straining of the organs, so also is it in all the remaining transitions, as soon as the attempt is made to extend the action by which the lower tones are formed beyond the given limits of the same. These transitions, which cannot be extended without effort, coincide perfectly with the places where J. Müller had to stretch the ligaments of his exsected larynx so powerfully in order to reach the succeeding half-tone. Garcia likewise finds tones thus formed disagreeable and imperfect in sound (klanglos).
Usually, therefore, at the note do♯ (c♯¹) in the female voice, and la si♭ (a b♭) in the male voice, the vocal ligaments alone act in forming the sound, and throughout the register are moved by large, loose, full vibrations (Totalschwingungen). But the instant the vocal ligaments are deprived of the assistance of the arytenoid cartilages, they relax and appear longer than at the last tone produced by that aid. But with every higher tone they appear again to be stretched shorter and more powerfully up to fa fa♯ (f¹ f♯¹), the natural transition of both the chest and falsetto registers, as well in the male as in the female. The larynx is perceptibly lower in all the tones of the chest register than in quiet breathing.